Bsi bs au 138a 1980 (2000)

BRITISH STANDARD AUTOMOBILE SERIES BS AU 138a 1980 Specification for Dimensions of “contact” type couplings for air pressure braking systems on trailers and semi trailers and their towing vehicles, an[.]

Specification for

U C 6 9.1 0 3.5:6 – 5 2.5

This Bri shStan ard, ha ing

b en pre ared u der the

directonof the Automo ile

Stan ards Commi e ,was

published u der the authoriy

ofthe Ex cutv Bo rd an

comesinto efect on

2 No emb r1 8

© BSI0 -2 0

The folowing BSI references

relate to the work on this

stan ard:

Commi e reference AUE/

-Draft for comment7 / 71 3 DC

ISBN 0 5 0 1 5 6 6

This BritishStand rd has be n prep red u der the direction of the Automobie

Stand ards Commit e and super edes BS AU5:19 3, except in reg ard to its

a pl cation to v acu m brake sy stems, and BS AU13 :19 7 BS AU13 :19 7is

withdrawn on publcation of this edition BS AU5 is not withd rawn

This ed ition of this stand ard makes no fu d mental chang es to these earl er

stand ard s but takes ac ou t ofchang es in normal practice since they were

is ued and clarifies certain d etais, p rticularly with reg ard to the operation

ofthe self-sealng v alv es

The form of couplng and lay out of coupl ng s specified in this stand rd

constitute a sy stem for use on any vehicle hav ing a two- or thre - ne air

pres ure brake sy stem

A British Stand rd do s not purport to include al the neces ary prov isions of

a contract User of British Stand ard s are responsible for their cor ect

a pl cation

Compl anc with a British Standard does not of itselfconfer imm unity

f om leg al o l g ations

Sum m ary of pag es

This d ocument comprises a f ont cov er, an insid e font cov er, p g esi andi ,

p g es1 to10 and a b ck cov er

This stand rd has be n upd ated ( se copy rig ht d ate) and ma hav e had

amend ments incorporated This wi l be indicated in the amendment ta le on

the inside f ont cov er

Am endm ents is ued sinc publ cation

Amd No Date of is ue Comments

Foreword Inside font cov er

Fig ure 1 — C ty pe male couplng with self-sealng v alv e 4

Fig ure 2 — C ty pe female coupl ng with operating ad aptor 5

Fig ure 4 — C ty pe female coupl ng with self-seal ng v alv e 6

Fig ure 5 — CA ty pe female couplng with self-seal ng v alv e 7

Ta le 2 — Summary of dimensions for articulated v ehicles 2

1 Scope

This BritishStand rd specifies the dimensions

neces ary to ensure the cor ect mating of “ ontact

couplng s for con ecting the air pres ure brake

sy stems of towing v ehicles to trai er or

semitrai er , and the lay out of these con ections

Two ty pes of “ contact couplng are specified : the

C ty pe, an the CA ty pe;these two ty pes of coupl ng

are intentional y phy sicaly non- nter hang ea le

This stand rd specifies the folowing :

a) the form and dimensions for a C ty pe “ contact

couplng and for the self-sealng v alv e, operating

probe and operating a a tor that shal be fit ed

to one or the other of the member of the coupl ng

to ena le it to be used on the serv ice or emerg ency

lne of a two- ine or thre - ne air pres ure

sy stem;

b) the form and dimensions for a CA ty pe

“ contact couplng an for the self-sealng v alv e

on the female couplng to ena le it to be used on

the second ry l ne of a thre - ine air pres ure

brake sy stem;

c) the g eneral lay out and location of flexible

hoses/tubes and C ty pe coupl ng s for v ehicles

using a two- ine air pres ure brake sy stem an of

the a ditional second ry lne and CA ty pe

couplng used in a thre - ine sy stem

2 Ref r nces

The fol owing stand rd s publ cations are refer ed to

in this stand ard

BS3 4 , ISO metr ic s r ew thr ea d s— Pa r t3: Limis

a nd toler a nc s fr fine pich thr ea d s (consta nt pich

s r ie )

BS5 0 , Spe ifica tion f r nylon tube—

Pa r t2:Pla stcized a nd u pla stcized nylon tubing

type 1 a nd12 fr us pr ima r ily in the a utomobie

ind ustr y

3 General requirements

3.1 Intro uction The req uirements of this

stand ard a ply eq ual y to both two- and thre - ne

air pres ure brake sy stems, except that in the case

of a two- ine sy stem, the second ary lne, its

couplng s and its stowing dev ice shal be omit ed

3.2 Manufacturer ’ responsibi ity The

man facturer of the traier shal sup ly and fit the

pipes and couplng s on the traier an shal prov ide

hoses in the case of drawb r traier Ev ery traier

shal be fit ed with an operating a a tor on the

serv ice l ne coupl ng whether or not the trai er is

intend ed to be coupled to a towing v ehicle with a

self-sealng v alv e

W ho v er instal s the fifth whe l or towing ho k on

the chas is shal sup ly , and fit on to the towing

v ehicle, the coupl ng s and self-seal ng v alv es, and

for articulated operation, the flexible tubes and

their stowing dev ices

The manufacturer of the towing v ehicle shal sup ly

and fit temporary blan ing plug s to the female

threa ed end s of the fixed pipes, read y for flexible

tube con ections, for articulated operation, or for

the couplng s, in the case ofdrawb r combinations

NOT W hen v hicles are u coupled,the con ectng

tub s/hoses should b safely housed in their stowing de ices

3.3 Colour co ing I a colour is used for a l ne, it

shal be as fol ows:

a) s r vic lne, y el ow or orang e;

b) emer gency lne, red;

c) s cond a r y lne, blue

3.4 Coupl ng s

3.4.1 Gener a l The ty pe of couplng to be used on

each lne at the a propriate location shal be as

specified in Ta le 1 The coupl ng s shal comply with

the form an d imensions specified in the fig ure

refer ed to in the relev ant entry of Ta le 1 As a

req uirement of Ta le 1, al coupl ng s that are fit ed

to, or hav e a fixed con ection with the towing

v ehicle shal hav e a self-seal ng v alv e W ith

reference to Fig ure 1to Fig ure 6,al couplng s shal

be threa ed to a depth of15mm ful leng th of

threa Some entries in Ta le 1specify the inclusion

of a self-seal ng v alv e or operating a a tor in the

coupl ng ; the req uirements for these components

are as folows

3.4.2 Self-s a ling va lve.A male couplng fit ed with

a self-seal ng v alv e shal be so ar ang ed to open only

when the as embly is con ected to a female

coupl ng A female couplng fit ed with a self-sealng

v alv e shal be so ar ang ed to open only when the

as embly is connected to a male couplng

A male coupl ng ( fit ed with a self-sealng v alv e) on

a serv ice lne shal be conspicuously marked to

ensure that the as embly is coupled only to a female

coupl ng that has an operating a a tor

3.4.3 O per a ting a d a ptor The operating ad aptor

fit ed to the female coupl ng of a serv ice l ne shal be

of the ty pe shown in Fig ure 2 and shal incorporate

an integ ral tip The tip shal be so ar ang ed that it

wi open the self-sealng v alv e in the male member

when the as embly is con ected to it For this

purpose, the integ ral tip of the a a tor shal :

a) be positioned ac ording to the dimension

specified in Fig ure 2( a); a nd

b) be so sha ed that it projects into the no zle of

the male member without foul ng it; a nd

Ta le 1 — Coupl ng s

c) ofer the minimum restriction to the flow of air;

a nd

d ) be suficiently robust or of a material to resist

the efects of cor osion

4 Articulated vehicles

4.1 Arrang ement and location ofbraking

conne tions Braking connections on articulated

v ehicles shal consist of:

a) fixed pipes on the towing v ehicle;

b) flexible tubes at ached to these pipes;

c) flexible tube stowing dev ices mou ted on the

towing v ehicle;

d ) for each l ne, a set of mating couplng s, one of

which is at ached to the flexible tube, the other

being fixed to the semi traier

The coupl ng inter ace shal thus be at the

semi traier

The location of the braking con ections, flexible

tubes an stowing d ev ices on the towing v ehicles

an semi traier using the two- or thre - ne

sy stem shal be as shown in Fig ure 7

NOT The fle ible tub sup orts are not shown in Fig ure 7 an

should b located in a conv nient p si on ( se 4.3.2)

Dimensions shown in Fig ure 7 shal be as specified

in Ta le 2

Table 2 — Sum m ary of dim ensions for

articulated vehicles

4.2 Fixed coupl ng s on sem i-traier

4.2.1Hor izonta l loca tion o couplngs The coupl ng s

for the serv ice lne and emerg ency lne shal be

fit ed on the font of the semi traier as nearly as

practica le eq uidistant f om the v ertical centrelne

of the semitrai er and f om20 mm to4 0mm

a art ( dimension G) The second ry lne couplng

shal be betwe n the serv ice and emerg ency

couplng s

4.2.2 Height o couplngs The coupl ng s shal

project at an ang le of0° to15° d ownward s fom the

horiz ntal and the heig ht to the centrelne of the

couplng s when fit ed shal be betwe n5 mm

and6 0mm a ov e the face of the fifth whe l

( dimension B)

4.3 Fixed conne tion on towing vehicle

4.3.1 Pipe

4.3.1.1 Hor izonta l loca tion o pipe The towing

v ehicle shal be fit ed with thre pipes as shown

inFig ure 7 The serv ice lne pipe and emerg ency

lne pipe shal be fit ed as nearly as practica le

eq uidistant fom the centrelne of the towing v ehicle

an f om20 mm to4 0mm a art ( d imension G)

The pipe for the second ary lne shal be betwe n the

serv ice pipe and emerg ency pipe

4.3.1.2 B or e The pipes shal hav e a nominal bore

of9mm for the serv ice l ne and the emerg ency lne,

and1 mm for the second ary lne

4.3.1.3 Pipe end s The pipe end s shal hav e an

M2 ×1.5–6H female threa comply ing with the

req uirements of BS3 4 -3 an shal be ta ped to a

d epth of15mm ful leng th of threa

Couplng location

Couplng ty e

Se vic lne Em ergency lne Se ond ry lne

Articulated

v ehicle

Coupl ng on

semi traier

Female C ty pe+

operating a a tor

( Fig ure 2)

Male C ty pe

( Fig ure 3)

Male CA ty pe

( Fig ure 6)

Coupl ng on rear

of flexible tube

Male C ty pe+

self-seal ng v alv e

( Fig ure 1)

Female C ty pe+

self-seal ng v alv e

( Fig ure 4)

Female CA ty pe+

self-seal ng v alv e

( Fig ure 5)

Drawb r

combination

Coupl ng on

towing v ehicle

Male C ty pe+

self-seal ng v alv e

( Fig ure 1)

Female C ty pe+

self-seal ng v alv e

( Fig ure 4)

Female CA ty pe+

self-seal ng v alv e

( Fig ure 5)

Coupl ng on f ont

of traier-mou ted

hose

Female C ty pe+

operating a a tor

( Fig ure 2)

Male C ty pe

( Fig ure 3)

Male CA ty pe

( Fig ure 6)





































Dim ension ( se Fig ure 7)

H +15

0

4.3.2 Flexible tube stowing d evic s Stowing d ev ices

shal be prov ided on the b ck of the ca , shal

sup ort the flexible tubes as far as is pos ible clear

of the chas is fame of the towing v ehicle when they

are not connected to the semi trai er, shal aford

a eq uate protection ag ainst d mag e and shal

in ibit entry of moisture an dirt

4.4 Flexible tubes

4.4.1 Type, a tta chment a nd sup or t The tube shal

be flexible ny lon tube comply ing with the

requirements of BS5 0 -2 The coied ny lon tube

shal be ar ang ed g eneraly as shown in Fig ure 7

Any sup ort shal be flexible, such that the slack of

the tube d oes not make contact with any p rt of the

towing v ehicle or its fit ing s

4.4.2 Tube end s The ends of the towing

v ehicle-mou ted tubes that are to receiv e the

couplng s shal be male M2 ×1.5–6g threa ed

con ections, threa ed to a leng th of1 mm,

comply ing with the req uirements of BS3 4 -3

4.4.3 Dimensions

4.4.3.1 B or e The nominal bore of the flexible tube

shal be as fol ows:

a) for serv ice l ne and emerg ency l ne, 9mm;

b) for second ry l ne,1 mm

4.4.3.2 Length The coied ny lon tube shal be of

suficient leng th so that it wi rea i y stretch to the

dimension J plus7 0mm, where J is the d istance

f om the b ck of the ca ( or any projection f om the

ca l kely to foul the semitrai er) to the centrel ne

of the rear a le, as shown in Fig ure 7

4.5 Tit cabs Special prov ision shal be mad e for

the tube sup orts and stowag e dev ices on an

articulated v ehicle with a tit ca

5 Dra wbar combina tions

5.1 Arrang em ent and location of braking

conne tions Braking con ections on d rawb r

combinations shal consist of:

a) flexible hoses taken d irectly f om the trai er

forecar iag e;

b) stowing d ev ices mounted on the d rawb r

traier;

c) for each lne, a set of mating couplng s, one of

which is at ached to the flexible hose, the other

being fit ed to the towing v ehicle

The couplng interace shal th s be at the towing

v ehicle

The location of the braking con ections an flexible

hoses on the towing v ehicles and d rawb r trai er

using the two- or thre - ine sy stem shal be as

shown in Fig ure 8

NOT The fle ible hose sup orts are not shown in Fig ure 8 an

should b located in a conv nient p si on ( se 5.3.2)

5.2 Fixed coupl ng s on towing vehicle

5.2.1 Hor izonta l loca tion o couplngs The couplng s

for the serv ice l ne an emerg ency l ne shal be

fit ed on the rear of the towing v ehicle as nearly as

practica le equidistant f om the v ertical centrelne

of the v ehicle an f om5 0mm to7 0mm a art

( d imension C), located as shown in Fig ure 8 The

second ary lne shal be on the same side as the

emerg ency couplng Dimension Z shal be7 mm

minimum

The face of the fixed p rt of the female C ty pe

coupl ng to the centrel ne of the towing pin

( d imension B ) shal be15 mm ma imum

and5 mm minimum, with the other couplng s

mou ted a proximately in lne, as shown

in Fig ure 8

5.2.2 Height o couplngs The couplng s shal

project at an ang le of0° to15° downwards f om the

horiz ntal and shal al be on the same horiz ntal

plane The centrelne of the coupl ng s shal

be20 mm ma imum and0mm minimum

v erticaly below the centrel ne of the towing jaw

( d imension A )

5.3 Pipes and conne tions on drawbar trai er

5.3.1 Pipe and hos s

5.3.1.1 Loca tion Flexible hoses shal be ru directly

f om the traier forecar iag e, and shal be secured at

a point near the a ex of the drawb r ( se Fig ure 8)

The leng th of hoses shal be such that, when coupled

to the towing v ehicle, the ma imum ang le of the

drawb r centrelne with the long itud inal a is of the

towing v ehicle of9 ° either wa can be at ained

whie at the same time permit ing a v ertical ang ular

mov ement of20° minimum a ov e or below the

horiz ntal position For ang les les than6 ° to

either side there shal be complete f e dom of lateral

mov ement without any tension on the hoses W hen

in the straig ht ahea position with the drawb r at

its normal operating heig ht, any hose shal not sa

below a l ne, projected f om the face of the fixed p rt

of the coupl ng s, at an ang le of20° below the

horiz ntal centrel ne of the couplng

5.3.1.2 B or e The pipes and hoses shal hav e a

nominal bore of9mm for the serv ice lne an the

emerg ency lne, and1 mm for the second ry lne

5.3.1.3 Hos end s The ends of the trai er-mou ted

hoses that are to receiv e the couplng s shal be male

M2 × 1.5–6g thread ed con ections, thread ed to a

leng th of1 mm, comply ing with the req uirements

of BS3 4 -3

5.3.2 Hos stowing d evic s Stowing dev ices shal be

prov id ed on the trai er so as to sup ort the hoses,

shal aford a equate protection ag ainst d mag e

and shal in ibit the entry of moisture an d irt

NOT Detail dimensions for the coupling are g iv n in Fig ure 3

All dimensions in milimetres

Fig ure 1 — C type male coupl ng with self- seal ng v lve

NOT Detail dimensions for the coupling are g iv n in( b).

( a) General ar ang ement of coupling wih o eratng ada tor fi ed

( b) Detail dimensions of coupling

All dimensions in milimetres

Fig ure 2 — C type fem ale coupl ng with o erating a a tor

Fig ure 3 — C ty e m ale coupl ng

NOT Detail dimensions for the coupling are g iv en in Fig ure 2( b)

All dimensions in milimetres

Fig ure 4 — C ty e female coupl ng with self- seal ng v lve